One form of prior art system of this character forms the subject matter of assignee's U.S. Pat. No. 3,788,527, which depicts the manner in which an accumulator connected to a container via a discharge port is charged with compressed air by means of a valving system which closes off the discharge port while the accumulator is being charged, thus storing a certain volume of air under pressure. A quick-release valve connects the charged accumulator to the interior of the container and produces the equivalent of a dull "explosion" that effectively breaks up the bridged material.
In that patent, the aerator, which contains the valving, is a part of the accumulator in the sense that part of it is coaxially within the accumulator, which enables the achievement of certain advantages, as where it is desired to weld the discharge pipe to the container, one example being a relatively tall container in the form of a silo. In such a case, several aerator-accumulator units must be used where the silo volume is quite large, mainly because the welded-on construction does not readily permit changing a mounted unit to a new position.
In assignee's copending U.S. Pat. application Ser. No. 502,547, filed Sept. 9, 1974, the patented structure is improved to the extent that it provides separable flange mountings for the aerator so that, if required, the unit may be moved readily from one position to other positions. Also in that application, the valving system is changed to a coaxial piston seating on a stop or spacer included as a separable part of the flange-to-flange connection between the aerator body and the accumulator.